When a mobile communication terminal moves geographically between cells of different base stations, the connection with the mobile communication terminal is transferred between the base stations. This is known as handover and has been implemented in most mobile communication networks.
Whether to perform a handover often depends on signal levels of two base stations as measured by the mobile communication terminal. However, handover problems do sometimes occur when handing over from a source base station to a target base station, e.g. by the mobile communication terminal losing the radio link to the target base station or establishing a connection with a third base station. Knowledge of such events assists in controlling whether a handover is to be triggered or not.
However, in heterogeneous environments with base stations of different configurations, the various types of base stations handle these events differently which can easily create a chaotic situation where different base stations handle the handover issues differently. This can lead to incorrect conclusions when expected handover issue messages are not received, either due to the issue not occurring or the base station not having the capability to send such handover issue messages.